Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/04—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers only
  • C08G65/06—Cyclic ethers having no atoms other than carbon and hydrogen outside the ring
  • C08G65/08—Saturated oxiranes
  • C08G65/10—Saturated oxiranes characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
  • C08G65/2642—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds characterised by the catalyst used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
  • C08G65/2642—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds characterised by the catalyst used
  • C08G65/2645—Metals or compounds thereof, e.g. salts
  • C08G65/2648—Alkali metals or compounds thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/32—Polymers modified by chemical after-treatment
  • C08G65/329—Polymers modified by chemical after-treatment with organic compounds
  • C08G65/331—Polymers modified by chemical after-treatment with organic compounds containing oxygen
  • C08G65/3311—Polymers modified by chemical after-treatment with organic compounds containing oxygen containing a hydroxy group
  • C08G65/3312—Polymers modified by chemical after-treatment with organic compounds containing oxygen containing a hydroxy group acyclic

Definitions

• the present invention relates to capped polyoxy­alkylene block polyethers. More particularly, the invention relates to an improved process for preparing such capped polyoxyalkylene block polyethers in high yield.
• Polyoxyalkylene block polyethers are well known commercial products having many uses, the most important of which is their use as nonionic surfactants.
• Polyoxyalkylene block polyether surfactants generally have both hydrophobic and hydrophilic blocks, and are described, for example, by Lundsted in U.S. Patent 2,674,619 and by Jackson and Lundsted in U.S. Patents 2,677,700 and 3,036,118. These references also disclose the preparation of such polyoxy­alkylene block polyethers by oxypropylating an initiator molecule possessing two or more active hydrogens in the presence of a basic catalyst such as sodium or potassium hydroxide.
• a basic catalyst such as sodium or potassium hydroxide.
• the polyoxypropylene hydrophobe is then oxy­ethylated to produce external hydrophiles, or, in certain cases, the oxypropylation and oxyethylation may be reserved to produce "reverse" non-ionic surfactants having an internal hydrophile and external hydrophobes.
• Normal polyoxyalkylene block polyethers are hydroxyl terminated. Frequently, the nature of hydroxyl functionality is such as to impart undesirable properties in specific applications.
• the polyoxyalkylene block polyether is difunctional, one of the hydroxyl functional­ities may be eliminated by the expedient of begining with a monofunctional inititator and appropriately altering the sequence of oxyalkylation.
• a triblock polyoxyalkylene polyether may be conventionally prepared, as shown in the reaction scheme below, by first oxypropylating a difunctional initiator molecule followed by oxyethylation.
• -OP- and -PO- represent oxypropyl residues derived from propylene oxide while -OE- and -EO- represent analogously derived oxyethyl groups.
• An analogous monofunctional, mono-capped triblock polymer may be prepared by starting with a monol, R-OH, such as methanol, butanol, fatty alcohols, alkylphenols, or benzyl­alcohol and altering the oxyalkylation sequence as follows:
• a monol, R-OH such as methanol, butanol, fatty alcohols, alkylphenols, or benzyl­alcohol
• Such mono-capped block polyethers where the cap is joined to the block polyether by an ether linkage are hydrolytically stable and have been shown to possess substantially dif­ferent physical and chemical properties as compared to their non-capped analogues, including modified surface activity and increased thermal stability.
• di-capped block poly­ethers In the past, similar di-capped block polyethers could be prepared by first forming a mono-capped polyether and then joining two such polyethers utilizing a difunc­tional "linking" or "bridging" reagent.
• a diisocyanate is used as the "linking" reagent.
• R ⁇ in the diisocyanate may be aliphatic or aromatic.
• such compounds contain two urethane linkages which are less stable, both hydrolytically and thermally, then a purely ether linket molecule.
• An alternative to such a process is the prepara­tion of a mono- or difunctional molecule followed by mono­capping or dicapping, respectively, utilizing traditional capping reagents.
• capping is traditionally performed, for example, as in U.S. Patent, 3,393,242, by means of reaction of the hydroxyl functional polyether with an alkali metal or alkali metal alkoxide followed by reaction with an alkyl halide.
• alkyl halide For example: A methyl capped polyether is the result.
• Other capping agents such as dialkylsulfates may also be used in this process in place of the alkyl halide.
• capping efficiency seldom, if ever, approaches 100 percent of theoretical. Even when an excess of the relatively expensive capping reagents are utilized, the capping efficiency does not generally exceed 90 percent of theoret­ical and is frequently far less.
• the process of the subject invention applies to the capping of any polyoxyalkylene block polyether con­taining one or more polyoxyethylene hydrophiles.
• the polyoxyalkylene polyethers are mono-capped polyoxyalkylene block polyethers prepared by sequentially oxyethylating, oxypropylating, and again oxyethylating an appropriate monol.
• conventional, non-capped polyoxyalkylene di- and higher hydroxyl functional poly­ethers may also be subjected to the subject process.
• the polyoxyalkylene polyethers to be capped are prepared by conventional methods, with the exception that the oxyethylation, and preferably both the oxyethylation and oxypropylation (or oxyalkylation with another higher alkylene oxide, i.e., butylene oxide) of the initiator or intermediate are catalyzed with cesium hydroxide as opposed to conventional sodium or potassium hydroxide catalysis.
• the oxyalkylations are performed sequentially, i.e., the various alkylene oxides are added substantially as individual components and not as mixtures.
• sequential oxyalkylating is meant just such oxyalkylation with substantially pure alkylene oxides but with the sequence of oxyalkylation in any order. Thus oxyethylation may be followed by oxypropyla­tion, or the reverse.
• Suitable initiators contain at least one active hydrogen which is capable of undergoing oxyalkylation.
• active hydrogen is capable of undergoing oxyalkylation.
• examples are aliphatic monols, diols, and polyols such as methanol, ethanol, propanol, butanol, fatty alcohols, ethylene glycol, propylene glycol, butylene glycol, glycerine, glucose, sucrose, and methyl and ethyl carbitols; phenols such as ocytl and nonyl phenol, hydroquinone, resorcinol, bis(4-hydroxyphenyl)methane; cycloaliphatic alkanols such as cyclohexanol, and 1,4-cyclohexane diol; aliphatic cycloaliphatic alkanols such as cyclohexane dimethanol, and the like. This list is illustrative only and not exhaustive.
• potassium hydroxide may be used as initial catalyst, especially when the hydrophobe is of modest equivalent weight, i.e., equivalent weights of less than 2000, preferably less than 1500.
• equivalent weights i.e., equivalent weights of less than 2000, preferably less than 1500.
• the residual potassium hydroxide catalyst is preferivelyably removed prior to additional oxypropylation to higher molecular weights, and, in any case, before oxyethylation.
• polyether preparation is otherwise conventional and well known to those skilled in the art. Examples of such preparation may be found, for example, in the treatise by Schick entitled Nonionic Surfactants, and in U.S. Patents 2,674,619, 2,677,700, and 3,036,118, which are herein incorporated by reference.
• the amount of cesium hydroxide catalyst utilized is the same as that utilized when sodium hydroxide or potassium hydroxide is the catalyst, on a mole-to-mole basis. Generally, from 0.005 to about 5 percent, preferably from 0.005 to 2.0 percent, and most preferably 0.005 percent to 0.5 percent by weight of catalyst relative to the finished product is utilized.
• the catalyst composi­tion during oxyethylation should contain a major part of cesium hydroxide. Up to 50 mole percent of potassium or sodium hydroxide may be tolerated, however, generally less than 20 mole percent, and preferably less than 10 mole percent of non-cesium hydroxide catalysts relative to total catalyst is desirable. Cesium methoxide and other highly basic cesium salts may also be used if desired.
• the hydrophobe of the polyoxyalkylene block polyethers of the subject invention are derived from a higher alkylene oxide, or from tetrahydrofuran.
• high alkylene oxide is meant alkylene oxides having from 3 to about 18 carbon atoms in the alkylene moiety.
• the hydrophobe is preferably a polyoxypropylene hydrophobe, other hydrophobes based on higher alkylene oxides such as 1,2-butylene oxide and 2,3-butylene oxide may also be used.
• the hydrophobe also can be derived from C8 to C18 olefin oxides, or from the polymeri­zation of tetrahydrofuran.
• the preferred oxyalkylation temperature is from 100°C to 145°C at a pressure of less than about 95 psig.
• Capping of the block polyethers may be performed in the conventional manner, for example as detailed in U.S. Patent 3,393,242, which is incorporated herein by refer­ence.
• the capping is performed by converting the polyoxyalkylene block polyether to its alkali metal salt by the use of an alkali metal or strong alkali metal base, e.g., sodium metal, sodium hydride or sodium methoxide.
• the polyoxyalkylene salt is then reacted with a suitable alkyl, cycloalkyl, or aralkyl halide.
• the reagents are generally utilized in approximately a 10 percent molar excess based upon the functionality of the polyether.
• a block polyether is prepared conventionally as described above.
• the initiator is tetrakis[2-hydroxy-­propyl]ethylenediamine which is oxypropylated at a tempera­ture of 100°C, using conventional KOH catalysis at a catalyst concentration of 0.08 percent by weight relative to the final product (post oxyethylation) weight.
• a portion of the oxypropylated intermediate base is treated with magnesium silicate to remove residual KOH catalyst and analyzed.
• the c.a. 3900 Dalton molecular weight product has an unsaturation, expressed as mg. of KOH per gram of polyether, of 0.008.
• the remainder of the intermediate base is reacted at a temperature of 160°C with sufficient ethylene oxide to produce a polyoxypropylene­polyoxyethylene tetrol having a nominal molecular weight, based on ethylene oxide charged, of 39,500 Daltons.
• This product is treated with magnesium silicate to remove residual KOH catalyst and analyzed.
• the product has a measured unsaturation of 0.054 meq KOH/g.
• Several monocapped, tri-block polyethers are prepared conventionally through KOH catalysts.
• the initiator in each case is propylene glycol.
• the hydrophobe is prepared by the addition of 32 moles of propylene oxide forming a hydrophobe having a molecular weight of approx­imately 1900 Daltons.
• the final hydrophiles are prepared by adding ethylene oxide at a temperature of 145°C. The reactor is maintained at the reaction temperature following the final ethylene oxide addition for a time sufficient to ensure that virtually all the ethylene oxide has reacted. The product is then vacuum stripped and the catalyst removed by treatment with magnesium silicate.
• polyethers A and B contain 6.4 and 28 moles of ethylene oxide, respectively, and have molecular weights of c.a. 2200 Daltons 3100 Daltons. Both triblock polyethers correspond to the structure:
• the polyethers prepared above are capped by first forming the sodium salt of the monocapped polyethers by stripping for 30 minutes at 125°C and ⁇ 10 torr pressure, padding with nitrogen, and reacting with a 5 or 10 percent molar excess of sodium methoxide, NaOCH3. Following removal of methyl alcohol in vacuuo , the reaction mass is cooled to 70°C and padded with nitrogen.
• the methyl dicapped product is prepared by addition of a 5 or 10 percent molar excess of methyl chloride over a time period of about two hours. The amount of capping reagent is determined from the hydroxyl numbers of the uncapped polyethers.
• the dicapped polyethers correspond to the formula: Table I summarizes the results of capping conventionally prepared polyethers A and B where a KOH catalyst is used as the oxyalkylation catalyst. Table I indicates that even with 10 percent molar excess of capping reagents the products still retain appreciable hydroxyl numbers, indicating considerable amounts of hydroxyl terminated polyether still present. Table I also indicates that the capping efficiency at 10 percent molar excess of expensive capping reagents averages only about 84 percent.
• Two monomethyl capped triblock polyethers are prepared using cesium hydroxide as the oxyalkylation catalyst.
• the initiator is methyl carbitol.
• Initial oxyalkylation is with ethylene oxide at a temperature of 135°C to form a hydrophile whose equivalent weight is one-­half the total hydrophile weight.
• the polyoxypropylene hydrophobe is prepared by the addition of approximately 32 moles of propylene oxide at a temperature of 115°C, forming a hydro­phobe having a weight of approximately 1900 Daltons.
• the terminal hydrophile is formed by the addition of the appropriate amount of ethylene oxide, again at 135°C.
• the two polyethers produced by this process polyethers Al and Bl, contain 6.4 and 28 moles of ethylene oxide and have molecular weights of 2000 and 3200 Daltons, respectively.
• Dicapped polyethers are prepared from the mono­methyl capped polyethers by the same procedure utilized in Comparative Examples 1-4. A 10 percent molar excess of capping reagents calculated from the polyethers' hydroxyl numbers is used. The results of the capping operation are summaried in Table II. As can be seen from the table, the capping efficiency is much higher than the capping efficiencies of the comparative polyethers. The hydroxyl numbers are also correspondingly lower.

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• 1987
  • 1987-10-29 CA CA000550559A patent/CA1312399C/fr not_active Expired - Lifetime
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